The image came into better focus when they incorporated a spatial statistical method called spatial autocorrelation, which allowed researchers to look at the degree to which pollution levels and allergic diseases were related in much greater detail and in smaller geographic areas of the city over five years.

Soojin Min PhD’18, who received her doctoral hood this summer, is one of the authors of the study.

“This paper introduces a new methodology for investigating and solving existing public health problems,” said author Soojin Min PhD’18, who graduated in August.

By addressing spatial autocorrelation, researchers pinpointed clusters — “hotspots” — in the city with high concentrations of pollutants and high prevalence of allergic diseases. They found that some of the subdistricts did not follow national patterns. For example, the rates of allergic rhinitis, also known as hay fever, increased in half of the districts but decreased in others over five years.

Researchers analyzed daily measurements of major air pollutants at 25 monitoring stations in Seoul and health data on severe or acute asthma, atopic dermatitis, a common type of eczema, and allergic rhinitis from 2011 to 2015. The pollutants included PM10, or small particles of pollution. They also calculated the number of cases of the allergic diseases in each of the city’s 423 subdistricts, which are smaller than a U.S. ZIP code area but larger than a typical neighborhood.

Dr. Dohyeong Kim

By analyzing the data at the subdistrict level, the study will allow South Korean officials to target limited resources to address the problem, Kim said.

“Through our study, we got a new lens to look at the environment disease mechanism that was not visible using the old lens. We argue that our lens is a little better to look at what’s really happening,” Kim said. “It’s really important from a public health perspective. If we have evidence that PM levels are associated with allergic disease rates in certain areas, we can locate resources there to tackle the problem.”

The study was the third that Min co-wrote while working on her doctorate in public policy and political economy. Min also worked with Kim on a related 2016 study that used GIS tools to examine the association between PM10 and allergic diseases and a 2014 study that found a wide gap in compensation from a 2007 South Korean oil spill.

Now that she has graduated, Min has accepted a position at Boston Medical Center, where she will work on research projects involving pediatrics and public health. She said she chose to study at UT Dallas because her program allowed her to gain interdisciplinary expertise in subjects such as public health policy and geospatial information sciences.

“The program isn’t limited to just one field,” Min said. “It lets you explore your research interests.”

Min said she appreciated the opportunity to be part of research projects early in her doctoral studies.

“Dr. Kim encourages students to be part of his projects even if you’re not a fourth- or fifth-year PhD student. He sees your potential,” Min said. “It’s a great learning experience.”